The functions of the Tissue Procurement and Laboratory Core of the Oral Cancer Research Center will be to provide investigators with ready access to oral cancer tissue (squamous cell carcinoma), premalignant tissue (erythroplakia/leukoplakia), and control oral mucosa required to meet their research objectives. The Core will procure, partition, process, store, catalogue, and distribute oral neoplastic, preneoplastic and control tissues to participating investigators. Projects 1, 2 and 3 will be supported by this facility. Facilities for processing and storage of tissues will be provided by the Lurie Cancer Center of Northwestern University and the University of Chicago. A central log of all processed tissues will be kept by Dr. Dennis Solt, the principal investigator, at Northwestern University. For matters relating to human tissues, the Core will operate according to guidelines established by the Internal Advisory Board of the Oral Cancer Research Center and approved individual protocols as reviewed by the Institutional Review Boards at Northwestern University and the University of Chicago. Studies on paraffin-embedded sections and pharmacologic sampling will also be organized through this Core. The Core will keep a detailed record on each specimen obtained. Additional clinical data, when necessary, will be available through the Clinical Core Laboratory. At the present time, the latter will be necessary only for project 3.